The market for smart products is now large and diverse. Information on the energy consumption of devices in operation and in standby mode is particularly difficult to research. Nevertheless, it is worth taking a look at the data. Before purchasing, the following requirements should be clarified:

• Is my smartphone's operating system compatible with the device's control app?
• Does the product require a permanent connection to the internet? SIM cards or subscriptions usually incur ongoing costs.
• Can the device be used and controlled without a user account on a cloud platform or a subscription contract with the manufacturer?
• Is the existing internet connection on site sufficient to operate the device as desired?

It is also annoying when the cloud service is discontinued after a short period of use or when the manufacturer no longer offers security updates. These points should also be checked before purchasing the smart device. According to the Federal Environment Agency, the product's lifetime can serve as a guideline for the minimum period. For a heating control system, for example, this should be at least ten years.

Software has a decisive influence on the service life of smart products. When software causes technically intact products to become unusable, scientists refer to this as software obsolescence. The risk is often not apparent at first glance. For those who would like to know more, we have included a link to the article "13 steps against software obsolescence" by the Federal Environment Agency in the list of links below.

When it comes to heating and living comfort, the focus is on advertising the potential energy savings. Following the energy crisis in 2022 and against the backdrop of steadily rising energy costs, the use of smart heating technology seems like a good idea. Back in 2019, the North Rhine-Westphalia Consumer Advice Center commissioned a study on "Energy consumption and savings potential of smart devices." This study only took into account the pure energy consumption of the devices on site. The energy required to provide cloud servers, for example, was not covered by the study.

The study compared model households equipped with different smart home applications with a corresponding household that did not have smart home applications (reference household). Three scenarios were considered. Scenario 1 includes smart applications for saving energy, such as radiator thermostats, door/window contacts, or lamps with sensor control. In scenario 2, applications for increased security, such as cameras and smoke detectors, were added. Scenario 3 also uses comfort-enhancing applications, such as speakers, robot vacuum cleaners, and garden irrigation. In all three scenarios, an apartment and a house were compared.

Overall, the results show that smart energy applications can achieve heating energy savings of between 9 percent (apartment) and 14 percent (house). In scenarios 2 and 3, there are no additional energy savings. In contrast, all scenarios show an increase in electricity consumption compared to the reference household. In scenario 1, this increase is relatively small at 3 percent, but rises to 6 percent (apartment) and 12 percent (house) in scenario 2. In scenario 3, electricity consumption is even 11 percent (apartment) and 19 percent (house) higher than in the respective reference household without smart applications. The study was conducted with identical model devices so that the values are comparable. The complete study by the consumer advice center can be found in the list of links.

In addition, the individual electricity consumption of devices from different manufacturers can vary significantly. In January 2024, Stiftung Warentest published a test of robot vacuum cleaners. The annual electricity consumption was also calculated here, which varied between 12 and 119 kilowatt hours, depending on the manufacturer. Therefore, electricity consumption should also be taken into account when making a purchase decision.

When it comes to energy savings with smart, connected devices, people often point out the risk of a rebound effect. This happens when making a product more efficient leads to a change in how it's used, which ends up using the same amount of resources or even more.

An example: Mr. W. has made his home energy-efficient by installing smart heating thermostats and roller shutter and lighting controls. Now he can use his smartphone to set a lighting and heating schedule for the rooms and operate the roller shutters even when he is away from home. However, this also means that rooms that are not currently in use are automatically heated and the roller shutters are operated when the occupant is away. All of these actions are associated with energy consumption. In addition, the smart products communicate constantly with the control system, require electricity for standby mode, and the internet connection and servers for the cloud service also consume energy. This results in higher electricity consumption than when using the house peripherals without the smart applications.

The Federal Environment Agency has compiled a few tips to help you make purchasing decisions for smart devices:

• Give preference to products that can fulfill their purpose without an internet connection.
• Before purchasing, check what additional software and hardware requirements the connected product has.
• Make sure that the manufacturer guarantees security updates, software support, and cloud services for many years.
• Make sure that you can delete data yourself.
• Reconsider your usage behavior to avoid a rebound effect.

Environmental tip April 2024